Commit b25e271b authored by Jacob Pan's avatar Jacob Pan Committed by Alex Williamson
Browse files

vfio: Fix unbalanced vfio_df_close call in no-iommu mode 



For devices with no-iommu enabled in IOMMUFD VFIO compat mode, the group open
path skips vfio_df_open(), leaving open_count at 0. This causes a warning in
vfio_assert_device_open(device) when vfio_df_close() is called during group
close.

The correct behavior is to skip only the IOMMUFD bind in the device open path
for no-iommu devices. Commit 6086efe7 omitted vfio_df_open(), which was
too broad. This patch restores the previous behavior, ensuring
the vfio_df_open is called in the group open path.

Fixes: 6086efe7 ("vfio-iommufd: Move noiommu compat validation out of vfio_iommufd_bind()")
Suggested-by: default avatarAlex Williamson <alex.williamson@redhat.com>
Suggested-by: default avatarJason Gunthorpe <jgg@nvidia.com>
Signed-off-by: default avatarJacob Pan <jacob.pan@linux.microsoft.com>
Reviewed-by: default avatarJason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20250618234618.1910456-1-jacob.pan@linux.microsoft.com


Signed-off-by: default avatarAlex Williamson <alex.williamson@redhat.com>
parent d7b8f8e2

drivers/vfio/group.c

+3 −4
Original line number Diff line number Diff line
@@ -192,12 +192,11 @@ static int vfio_df_group_open(struct vfio_device_file *df) 
		 * implies they expected translation to exist

		 */

		if (!capable(CAP_SYS_RAWIO) ||

		    vfio_iommufd_device_has_compat_ioas(device, df->iommufd))

		    vfio_iommufd_device_has_compat_ioas(device, df->iommufd)) {

			ret = -EPERM;

		else

			ret = 0;

			goto out_put_kvm;

		}

	}



	ret = vfio_df_open(df);

	if (ret)

drivers/vfio/iommufd.c

+4 −0
Original line number Diff line number Diff line
@@ -25,6 +25,10 @@ int vfio_df_iommufd_bind(struct vfio_device_file *df) 


	lockdep_assert_held(&vdev->dev_set->lock);



	/* Returns 0 to permit device opening under noiommu mode */

	if (vfio_device_is_noiommu(vdev))

		return 0;



	return vdev->ops->bind_iommufd(vdev, ictx, &df->devid);

}